I live in a house built in the 40s. It has a distinctive smell that I call "old house smell." I've noticed a similar smell in other old houses. It's not necessarily a terrible smell, but i would like to change it. It can be altered somewhat by air fresheners, etc, but it never completely goes away. I'm sure those old houses that are rennovated on tv don't retain that smell, but unless I gut the house and start over, Is that just something I'm stuck with?

I don't mean to be an alarmist, but we had that experience and it turned out to be a slow gas leak on the old stove. You might want to have someone check it out. Or, it's probably a plumbing issue. So, either way a plumber could help.

Basically its down to ventilation.
Most smells degrade over time and disappear.
Try opening the windows during the summer.

When your home was built, it probably had lots of cracks and holes, all these coupled with open fires helped to keep the place smelling nice (apart from the smells of wood, coal and soot)

Now to save on heating it is probably sealed up, try opening the windows a small amount every warm day, perhaps in the morning and evening.

Do check out the corners of rooms and the spaces behind furniture and curtains for damp patches and mold, it may well be fruiting mold that you can smell.

Then have a good sniff when you come home to smell the improvement.
Other than that, a mechanical ventilation system, that can be programmed to come on for a short time, will in time solve the problem.

I have the same problem - somewhat. My house smells "musty" When I take clothes out of the closet or clothes/blankets/... out of the house, they smell old & musty. My husband thinks because our house is basically all wood (wood walls & ceilings) with a flat roof & really no ventilation.
Yuck - I hate it. Most of the times I have to febreeze the ____ out of ny clothes & throw them in the dryer before I can wear them.

I know the smell you are referring to. I do remodeling and live in an town with houses built in the 1700's. I noticed the smell in each house I work on. I noticed when renoving the old plaster, the wood has the same smell. If I am doing a complete remodel I will spray aluminum paint on the old framing and any wood exposed. This is the same thing I do on a fire job, It stops the smell. The way I look at the smell is, you know you have a well built house, not the junk some companies build in a week and are rotting away in 5 years. I have a customer that is in her 90's, she said she "airs ot the house on nice days". Enjoy

Ok, this is going to take some work but I know just the solution. Buy a pet product called anti icky poo. It is hard to find so buy it on the internet. Take a towel and wash the walls with it. Then wash the floors with it. You may have to do this several times - maybe 2 or 3 (but it works I swear) . It cleans the smell of urine, vomit, and even skunk. Another thing, when you clean it, do not dry it like you would when you wash the kitchen floors. Let it airdry. THis is what makes it work. It is an enzyme and needs to get into the walls and floors. You can even do this on hardwood floors, doors and metal - I have a boiler system and had to clean the heater things....I forgot what they are called hahaha. Another way to do this if you are repainting your house anyways is to paint all the walls with KILLS or BIN and then paint. It will cover up all smells as it is a really thick primer. They even have KILLS that covers smells. Good lucK~

Also check under the house if there's a crawl space. There needs to be a 6 Mil. plastic vaper barrier on the ground under it. Look to see if there's standing water under the house. If it's a shingled roof make sure there's a ridge vent on the peak of the roof. Make sure the soffit vents are not painted over or there's insulation in the attic covering them. Make sure there's working gutters.
Painting over will seal in the odor for a while but why not get rid of what's causing the odor in the first place.